The vegetables (and tempeh) are all meant to be cut into a similar shapes and thicknesses. By this we mean the onions are sliced, the celery is sliced on the bias, the green peppers are cut somewhere between batonnet and julienne — even the water chestnuts are sliced, rather than diced. This just gives the stir-fry another layer of texture and mouth-feel.
As for the amounts of certain ingredients, they are flexible. Meaning, if you really like lemongrass, garlic and spice, then you might want to add the higher amounts of those ingredients. Perhaps for the first time, start with the smaller amounts and then the second time, use the higher amounts — either way the stir-fry will still be delicious.
Combine the stock and
Fish-Less Fish Sauce in a small bowl. Set aside.
*Note: If you can, use fresh water chestnuts. They are superior in flavor and texture. To prepare the water chestnuts, simply cut off the top and bottom and peel the exterior with a vegetable peeler. Place into cold water to prevent them from oxidizing. Drain and slice just before using.
**Note: Vegan/vegetarian "chicken" flavored stock works really well in this recipe — see notes below for more information.